Anti-fogging device for endoscope

ABSTRACT

Anti-fogging system for an endoscope including an endoscope having an outer housing, an imaging arrangement, and a distal window. A filter lens is located at the distal window, with the filter lens allowing a first portion of electromagnetic light to pass therethrough while absorbing a second portion of electromagnetic light in order to heat the filter lens.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/155,480, filed Jan. 15, 2014, which claims the benefit of U.S.Provisional Application No. 61/753,695, filed Jan. 17, 2013, the entirecontents of each of which are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to an anti-fogging device for use inconjunction with an endoscope.

BACKGROUND OF THE INVENTION

An endoscope is a surgical tool designed to be placed inside a body inorder to provide a view of the interior portion of the body. Inendoscopic surgery, the endoscope is placed in the body at the locationat which it is necessary to perform a surgical procedure. Other surgicalinstruments are placed in the body at the surgical site. The surgeonviews the surgical site through the endoscope in order to assess theinterior portion of the body and to manipulate the other surgicalinstruments to perform the desired surgical procedure. The developmentof endoscopes and their companion surgical instruments has made itpossible to perform minimally invasive surgery that eliminates the needto make a large incision in the patient to gain access to the surgicalsite. Instead, during endoscopic surgery, small openings, calledportals, are formed. One advantage of performing endoscopic surgery isthat since the portions of the body that are cut are reduced, theportions of the body that need to heal after the surgery are likewisereduced. Still another advantage of endoscopic surgery is that itexposes less of the interior tissue of the patient's body to the openenvironment. This minimal opening of the patient's body lessens theextent to which the patient's internal tissue and organs are open toinfection.

During endoscopic surgery, the environment of the body cavity may poseproblems relating to proper operation of the endoscope. For example, thebody cavity may be characterized by high humidity and/or a hightemperature relative to that of the operating theater. Accordingly,inserting a relatively cold endoscope into the body cavity may result incondensation in the form of fogging on the surface of the endoscope andin particular on the optical window located at the distal end thereof.Such condensation may impair the transmission of information into theendoscope and thereby reduce the usefulness of the endoscope for theduration of the condensation, potentially prolonging the duration ofsurgery.

Various solutions to the fogging problem have been proposed. Given thatcondensation is a consequence of introducing a relatively cool objectinto the body cavity, one potential solution involves raising thetemperature of the endoscope prior to insertion into the body, as bywarm towels or warm baths. Another possible solution is to coat theaffected areas of the endoscope with fog-resistant coatings to reducethe adhesion of liquid particles to the endoscope. Further approachesare outlined in U.S. Pat. No. 4,279,246 entitled DEVICE FOR PREVENTINGCLOUDING OF AN OBSERVING WINDOW, U.S. Pat. No. 5,605,532 entitledFOG-FREE ENDOSCOPE, U.S. Pat. No. 5,647,840 entitled ENDOSCOPE HAVING ADISTALLY HEATED DISTAL LENS, and U.S. Pat. No. 5,910,106 entitled METHODAND APPARATUS FOR HEATING A SURGICAL INSTRUMENT, the entire contents ofall of which are hereby incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention are illustrated by wayof example and should not be construed as being limited to the specificembodiments depicted in the accompanying drawings, in which likereference numerals indicate similar elements.

FIG. 1 illustrates a perspective schematic view of an endoscopic systemaccording to the invention.

FIG. 2 is an enlarged longitudinal and fragmentary cross-sectional viewof the endoscope of FIG. 1, and a fragmentary view of the distal end ofthe cable associated with the light source.

FIG. 3A is an enlarged, longitudinal and fragmentary cross-sectionalview of the distal end of the endoscope of FIG. 1 as seen generallyalong line IIIA-IIIA in FIG. 2.

FIG. 3B is an enlarged end view of the distal end of the endoscope asseen generally along line in FIG. 3A.

FIG. 4A is an enlarged, longitudinal and fragmentary cross-sectionalview of the distal end of an alternative endoscope.

FIG. 4B is an enlarged end view of the distal end of the alternativeendoscope as seen generally along line IVB-IVB in FIG. 4A.

FIGS. 5A-5E illustrate flow charts for approaches for setting a powerlevel of a source of heating light of the present invention.

FIG. 6 is a schematic view of the endoscope system according to thepresent invention illustrating a sensor for reading a temperature of adistal window of the endoscope.

FIG. 7 is a side view of a distal end of the endoscope of the presentinvention configured to have a cap placed thereon.

FIG. 8 is a perspective view of a console or light source of theendoscopic system having a button thereon.

FIGS. 9A-9D illustrate flow charts for methods for determining if anendoscope includes a distal window of the present invention.

FIG. 10 is a schematic view of the endoscope system according to thepresent invention illustrating a detector for detecting reflection of aband of light from the endoscope.

FIG. 11 is a perspective view of a console or light source of theendoscopic system having a sensor thereon.

FIG. 12 is a schematic view of a first embodiment of a communicatingendoscope of the present invention.

FIG. 13 is a schematic view of a second embodiment of a communicatingendoscope of the present invention.

FIG. 14 is a schematic view of a third embodiment of a communicatingendoscope of the present invention.

FIG. 15 is a schematic view of a fourth embodiment of a communicatingendoscope of the present invention.

Certain terminology will be used in the following description forconvenience in reference only, and will not be limiting. For example,the words “forwardly” and “distally” will refer to the direction towardthe end of the arrangement which is closest to the patient, and thewords “rearwardly” and “proximally” will refer to the direction awayfrom the end of the arrangement which is furthest from the patient. Saidterminology will include the words specifically mentioned, derivativesthereof, and words of similar import.

DETAILED DESCRIPTION

FIG. 1 illustrates an endoscopic system 20 including an endoscope 22, atransmission cable 46, and a light source console 28. The endoscope 22is defined by an elongated and generally hollow shaft 23 with a distalend 27 configured for insertion within a body cavity. The hollow shaft23 also has a proximal end 24 which mounts thereon an eyepiece 25 fittedto provide a viewing port through which the surgeon views the surgicalfield (for example, directly or through a connection between a viewingport, a digital camera 73, and a display screen 75). A light port 58 maybe connected with light inputs to selectively transmit light to a targetvia the endoscope 22. In the illustrated embodiment, the light sourceconsole 28 sends electromagnetic waves to the distal end 27 of theendoscope 22 to heat the same to prevent fogging.

The light source console 28 selectively provides electromagneticradiation as imaging light for use in the operating theater forilluminating the surgical field. In the present embodiment, thecandlepower of the imaging light emitted from the light source console28 is selectively adjustable through manipulation of a sliding switch41. The light source console 28 also provides electromagnetic radiationas heating light to the distal end 27 of the endoscope 22 to preventfogging of the same as discussed in more detail below. Further, thelight source console 28 comprises a socket 43 to transmit theelectromagnetic radiation from the light source console 28 toinstruments such as the endoscope 22 via intermediary devices, such asthe transmission cable 46.

The illustrated transmission cable 46 is configured to transmit lightfrom a proximal end 54 of the transmission cable 46 to a distal end 56of the transmission cable 46 attached to the light port 58. Thetransmission cable 46 can comprise an optical fiber or optical fiberssuited to transmit electromagnetic radiation via total internalreflection of such radiation within the fiber material. The proximal end54 and the distal end 56 include terminal geometries, such as plugs,conducive to receiving and emitting, respectively, electromagneticradiation.

As shown in FIG. 2, the endoscope 22 contains a variety of internalmechanisms. For example, the shaft 23 houses therein an imagingarrangement, which in this embodiment includes an optical train 29comprised of one or more lenses suitably aligned to transmit an imagefrom the distal end 27 to the eyepiece 25. The shaft 23 incorporatestherein suitable mounting structures which maintain alignment of thecomponents of the optical train 29 toward the eyepiece 25, and includesthe light port 58 whereby electromagnetic radiation may be transmittedinto the endoscope 22 via the transmission cable 46. While the endoscope22 is illustrated as being rigid, it is contemplated that the endoscopecould be rigid, semi-rigid or flexible.

FIGS. 3A and 3B illustrate the structure of the endoscope 22 in greaterdetail at the distal end 27 thereof. The shaft 23 of the endoscope 22 isdefined by a substantially cylindrical and tubular outer housing 61 andan inner tubular housing 63 located within the outer housing 61. Theouter and inner housings 61, 63 are sized such that an annular space 60is defined therebetween which extends along a substantial portion of thelongitudinal extent of the shaft 23. A cylindrical optical fiber 64 islocated within the annular space 60 and extends from the distal end 27rearwardly to the proximal end 24 of the endoscope 22 to receiveelectromagnetic radiation transmitted into the endoscope 22 via thetransmission cable 46.

In the illustrated example, the inner tubular housing 63 enclosesinnermost functional components of the endoscope 22, such as the opticaltrain 29. The optical train 29 can comprise an image lens 71 at thedistal end 27 suitably fixed or connected to the inner surface of theinner tubular housing 63 with a corresponding generally annular imagelens casing 72. A distal window 99 is located at the distal terminus ofthe tubular outer housing 61, the inner tubular housing 63 and theoptical fiber 64. In one embodiment, the otherwise empty spaces in theoptical train 29, for instance the space between the image lens 71 andthe distal window 99, are hermetically sealed against the exterior ofthe endoscope 22 and filled with a specified fluid such as low-humiditynitrogen gas. Alternatively, one or more such spaces may be hermeticallysealed with respect to the exterior of the endoscope 22 andsubstantially devoid of fluid. The components and workings of theendoscopic system 20 as described above are conventional and furtherdescription is accordingly not provided herein.

The illustrated endoscope 22 includes the distal window 99 on the distalend 27 thereof. The distal window 99 allows the imaging light comingfrom the optical fiber 64 to pass therethrough for illuminating thesurgical field. After passing through the distal window 99, the imaginglight reflects off of matter in the surgical field and reflects backthrough and into the endoscope 22 through a center area of the distalwindow 99 to be passed to the eyepiece 25. The distal window 99,however, does not allow the heating light to pass therethrough in orderto absorb energy of the heating light to heat the distal window 99.Heating of the distal window 99 prevents moisture from condensating onan exterior surface 100 of the distal window 99, thereby preventingfogging of the endoscope 22. The distal window 99 can comprise anoptical absorbing element or an optical absorbing element in combinationwith another optical element (e.g., a fully transparent window).

In the illustrated example, the imaging light can come from a standard,unmodified source 102 of imaging light and the heating light isgenerated from a source 104 of heating light which adds infrared (“IR”)light (broad or narrow band) thereto (see FIG. 6). The light sourceconsole 28 thereby supplies the endoscope 22 with typical imaging light(e.g., visible light) and heating light in the form of IR light. Theendoscope 22 thereby emits imaging light to illuminate an inside of thebody cavity at the distal end 27 thereof and the distal window 99prevents condensation by quickly reaching body temperature throughabsorbing IR radiation from the IR light. In the present example, it iscontemplated that the desired temperature of the distal window 99 isapproximately body temperature.

It is contemplated that the distal window 99 could absorb specific bandsor the entire IR band. For example, the heating light could come from anarrow-band IR laser source (i.e., the source 104 of heating light inthis example) and the distal window 99 could be an absorbing band-stop,optically transparent IR filter. With the heating light coming from anarrow-band IR laser source and the distal window 99 being an absorbingband-stop, optically transparent IR filter, the remainder of the IR bandcan be available for use in current and future IR imaging products andtechnologies. It is contemplated that the choice of light bandwidths forthe heating light and the imaging light can be flexible. With anappropriate choice of camera, imaging light, heating light, and optics,an aspect of the present invention is to be fully capable of beingcompatible with endoscopy imaging systems using any choice of bandwidththroughout the ultraviolet, visible, and IR portion of theelectromagnetic spectrum. The heating light may also be selected fromany part of this spectrum, and can be chosen from outside of the imagingband in a region that can be absorbed by inexpensive window optics whilepassing the imaging bandwidth (which allows the window temperature andillumination brightness to be independently adjusted). In oneembodiment, the distal window 99 captures visible-light imagery and usesbroadband infrared light in the mid-IR range and is also fully capableof acquiring near IR-imagery. It is contemplated that the distal window99 can include a thickness of approximately 0.5 mm and have a diameterof about 0.5 mm to allow the distal window 99 to heat quickly andthoroughly without producing reflections of the imaging light whichenters the distal window 99.

FIGS. 4A and 4B illustrate an alternative embodiment for the endoscope22′, including a plurality of optical fibers 64′ formed into a circlewith the distal end 27′ including a ring 62′ containing therein distalends of the respective optical fibers 64′. In one embodiment, the ring62′ is defined by an adhesive which serves to fix the ends of theoptical fibers 64′ at the distal end 27′ of endoscope 22′ such that theends of the optical fibers 64′ are disposed in a generally annularfashion about the distal end 27′ for emitting light on the surgicalsite. For example, the ring 62′ may bind together a plurality of opticalfibers 64′ into a solid annular mass via adhesives that do notsubstantially impair the transmissive properties of the optical fibers64′.

Operation

The endoscope 22 is connected to the light source console 28 via thetransmission cable 46. Specifically, the transmission cable 46 attachesto the light source console 28 at the interface between the socket 43and the proximal end 54 and the transmission cable 46 attaches to theendoscope 22 at the interface between the light port 58 and the distalend 56. In one embodiment, the eyepiece 25 is operationally connected toan image sensor assembly or camera 73 comprising a CCD (charged coupleddevice) or CMOS sensor (complementary metal oxide semiconductor), whichimage sensor assembly provides the surgeon with a view of the surgicalsite on the display screen 75 (or a plurality of displays). Such animage sensor assembly or camera 73 may, for example, be provided at theproximal end 24 of the endoscope 22, adjacent the eyepiece 25. Thedistal end 27 of the shaft 23 is inserted into the body cavity of thepatient. Light is cast on the target area through actuation of a switch14 on the light source console 28 and corresponding transmission ofelectromagnetic radiation from the light source console 28, through thetransmission cable 46 and out the annular ring 62 of the optical fiber64 or optical fibers 64′ of the endoscope 22. Electromagnetic radiationin the form of imaging light at least partially reflects off the targetarea and the reflected light passes through the distal window 99, downthe optical train 29, and into the eyepiece 25. Furthermore, the heatinglight is absorbed by the distal window 99 to prevent condensation byquickly reaching body temperature through absorbing IR radiation fromthe IR light.

Power Level

An aspect of the present invention is to limit the power level of thesource 104 of the heating light (and thereby the heating light) to limitthe temperature of the distal window 99. A first approach is to maintainthe source 104 of heating light at a constant power level that defogs orprevents fogging of the distal window 99 with sufficient speed andconsistency, which is illustrated in the single method step 300 of FIG.5A. It is contemplated that the method step 300 may employ knowledge ofthe endoscope 22 attached to the light source console 28 that isprovided either manually by the user or automatically by transmission ofheating parameters via radiofrequency or infrared light or other meansfrom the endoscope 22 to the light source console 28. In the lattercase, the parameters may be specific to the endoscope 22 or parametersspecific to the individual endoscope 22 being used, with the parametersbeing measured in a factory during manufacture of the endoscope 22.

A second approach for limiting the temperature of the distal window 99includes a method 310 of measuring a temperature of the distal window 99to ensure that the distal window 99 does not rise above a desiredtemperature (see FIG. 5B). FIG. 6 illustrates the endoscopic system 20of the present invention including the light source console 28, thetransmission cable 46 and the endoscope 22. The light source console 28includes the source 102 of imaging light and the source 104 of heatinglight. The light source console 28 also includes a mirror 106 thereinthat reflects the heating light coming from the source 104 of heatinglight into a path of the imaging light coming from the source 102 ofimaging light.

In the illustrated method 310 of measuring a temperature of the distalwindow 99 of the second approach, the distal window 99 will reflect atemperature-dependent fraction of the imaging light back to the lightsource console 28 at step 312 (e.g., by having the distal window includea Bragg grating filter). The temperature-dependent fraction of theimaging light sent back to the light source console 28 will reflect offof the mirror 106 and be sent to a temperature reading system 108,wherein the temperate of the distal window 99 is calculated using thetemperature reading system 108 at step 314. It is contemplated that thetemperature reading system 108 can comprise a single or multiplephotodiodes with or without additional optical fibers or a spectrometersystem. The temperature reading of the distal window 99 made by thetemperature reading system 108 is used to modulate the heating lightoutput from the source 104 of heating light to bring the distal window99 to a desired temperature and to prevent overheating of the distalwindow 99 at step 316. The method 310 of measuring a temperature of thedistal window 99 can continuously monitor the temperature of the distalwindow 99 at step 314 to continuously adjust the power level of thesource 104 of heating light to maintain the desired temperature.

A third approach for controlling the power level and temperature of thedistal window 99 includes using a temperature sensitive cap 110configured to be positioned over the distal end 27 of the endoscope 22(FIG. 7) in a method 320 of measuring a temperature of the distal window99 (see FIG. 5C). The method 320 of measuring a temperature of thedistal window 99 includes positioning the temperature sensitive cap 110over the distal end 27 of the endoscope 22 for a short period of time(e.g., few seconds) before the distal end 27 of endoscope 22 ispositioned within the body cavity at step 322.

The illustrated temperature sensitive cap 110 positioned over the distalend 27 of endoscope 22 reports the temperature of the distal window 99to the light source console 28 (or control system thereof) over acommunication network 112 at step 324. As the temperature of the distalwindow 99 reaches the desired temperature (e.g., body temperature), acontroller (e.g., proportional-integral-derivative (PID) controller) inthe light source console 28 (or control system thereof) engages acontrol loop to compute the power needed at the source 104 of heatinglight to maintain the desired temperature (e.g., body temperature). Thecommunication network 112 can be temperature sensitive RFID technologythat reports the temperature of the distal window 99 to the light sourceconsole 28 (or control system thereof). Alternatively, temperaturesensors could be located within the temperature sensitive cap 110 formeasuring the temperature of the distal window 99 that communicates thetemperature of the distal window 99 to the light source console 28 (orcontrol system thereof) via a wired or wireless communication network112. It is contemplated that one method of communication may be to sendinfrared signals from the cap 110 back through the endoscope 22, throughthe transmission cable 46, and back to the light source console 28, witha detector in the light source console interpreting the infrared signalsto determine the temperature of the distal window 99. It is contemplatedthat the temperature reading sent to the light source console 28 couldbe above a desired temperature such that the light source console (ofcontrol system thereof) turns off the source of heating light. The RFIDtechnology or the temperature sensors can be passively powered or can beactively powered by a power source 120 within the temperature sensitivecap 110. The power source 120 can be a battery or a photoelectric solarcell than extracts energy from imaging light coming from the lightsource console 28 and out of the endoscope 22 through the distal window99. It is contemplated that the temperature sensitive cap 110 can bedisposable and/or sterilizable (e.g., by autoclaving).

In the illustrated example, the method 320 of measuring the temperatureof the distal window 99 using the temperature sensitive cap 110 includesadjusting the power level of the source 104 of heating light to adjustthe temperature of the distal window 99 at step 326. If the temperatureof the distal window 99 is determined to be at the desired level at step328, the power level of the source 104 of heating light is maintained atstep 330. If the temperature of the distal window 99 is determined tonot be at the desired level at step 328, the temperature sensitive cap110 remains on the endoscope 22 and the method 320 of measuring thetemperature of the distal window 99 returns to step 322.

A fourth approach for controlling the power level and temperature of thedistal window 99 includes using a user activated trigger or control in amethod 340 of powering the source 104 of heating light (FIG. 5D). Forexample, FIG. 8 illustrates the light source console 28 having a housing125 with a control mechanism 127 thereon. The control mechanism 127 canbe a button that is depressed for activating the source 104 of heatinglight for a finite amount of time. The method 340 of powering the source104 of heating light includes actuating the control mechanism 127 atstep 342. It is contemplated that the control system for the lightsource console 28 and/or the source 104 of heating light could track thenumber and/or frequency of depressions of the button to honor not morethan a selected number of depressions within a certain time frame toprevent overheating of the distal window 99 at step 344. If the controlmechanism 127 has not been depressed too many times in a certain timeperiod, the source 104 of heating light is activated at step 346. It iscontemplated that the control mechanism 127 could be a dial (or slideror similar mechanism) that controls the power of the source 104 ofheating light (e.g., higher power or lower power as the dial is moved orfrom a “temperature maintenance” power level to a higher “heating” powerlevel and vice/verse as the dial is moved). It is contemplated that thecontrol system for the light source console 28 and/or the source 104 ofheating light could automatically turn down the power level after acertain time period or after a certain amount of power has beentransmitted to the endoscope 22.

A fifth approach for controlling the power level and temperature of thedistal window 99 includes a method 350 of using the camera to activateor modulate the control system for the light source console 28 and/orthe source 104 of heating light when fog or condensation is detected bythe camera 73 as being on the distal window 99 (FIG. 5E). In the method350 of controlling the power level using the camera 73, the image isviewed by the camera 73 at step 352. If fog or condensation isdetermined to be on the camera 73 at step 354, the source 104 of heatinglight is activated at step 356. If fog or condensation is determined tobe on the camera 73 at step 354, the method 350 of controlling the powerlevel using the camera 73 returns to step 352 to view the image againusing the camera 73. Fog or condensation can be detected by the camera73 as being on the distal window 99 using an image-processing analysis.

Heating Window Sensing

An aspect of the present invention is to detect if the endoscope 22 hasa distal window 99 in order to prevent supplying heating light to theendoscope 22 if the endoscope 22 does not have the distal window 99. Ifthe endoscope 22 does not have a distal window 99, the heating lightwould pass through the endoscope 22 and into the patient.

A first method 400 (FIG. 9A) for determining if the endoscope 22includes the distal window 99 is to place a partially reflective opticalcoating or mirror 150 at the light port 58 of the endoscope 22. Asillustrated in FIG. 10, the partially reflective optical coating ormirror 150 could have a narrow band of reflectivity or multiple narrowbands of reflectivity of light as illustrated in graph 500. For example,the partially reflective optical coating or mirror 150 could have anarrow band of reflectivity or multiple narrow bands of reflectivity onthe order of single digit nanometer wavelengths. The first method 400(FIG. 9A) for determining if the endoscope 22 includes the distal window99 comprises emitting heating light with the source 104 of heating lightat step 402. The electromagnetic waves reflected off of the partiallyreflective optical coating or mirror 150 could be reflected off of themirror 106 that only allows light of certain wavelengths to passtherethrough as shown in graph 502 within the light source console 28 inorder to be read by a detector 152 at step 404. The partially reflectiveoptical coating or mirror 150 can allow the imaging light to passtherethrough as illustrated in graph 502 of FIG. 10.

Using the illustrated first method 400, the control system for the lightsource console 28 and/or the source 104 of heating light will allow thesource 104 of heating light to activate if the detector 152 senses thelight reflected from the partially reflective optical coating or mirror150 at step 406. However, if the detector 152 does not sense the lightreflected from the partially reflective optical coating or mirror 150 atstep 408, the control system for the light source console 28 and/or thesource 104 of heating light will not allow the source 104 of heatinglight to activate. Therefore, if the endoscope 22 does not have thepartially reflective optical coating or mirror 150, the source 104 ofheating light will not activate.

In an embodiment of the first approach for determining if the endoscope22 includes the distal window 99, the source 104 of heating light cansend out lower power IR sense pulses dichroically mixed with the imaginglight leading to the endoscope 22. Reflections of the IR sense pulsesare detected by the detector 152, which is capable of distinguishingmultiple bands of light and the intensities of the light. It iscontemplated that the band or bands of reflected light can be used toidentify the type and/or manufacturer of the endoscope 22 and thecontrol system for the light source console 28 and/or the source 104 ofheating light would only be activated when a particular type and/ormanufacturer of the endoscope 22 is identified in order to preventoverheating of the distal window 99. Alternatively, the control systemfor the light source console 28 and/or the source 104 of heating lightcould be altered depending on the particular type and/or manufacturer ofthe endoscope 22 identified. It is also contemplated that the lightsource console 28 could communicate with the camera 73 or the displayscreen 75 or control thereof to optimize the image passed through theendoscope 22 depending on the particular type and/or manufacturer of theendoscope 22 identified.

A second method 410 (FIG. 9B) for determining if the endoscope 22includes the distal window 99 is to emit a pattern of electromagneticwaves with the light source console 28 at step 412, send the pattern ofelectromagnetic waves through the endoscope 22 and have the camera orcontrol thereof look for the pattern. If the camera or control thereofidentifies the pattern at step 414, then the camera 73 or controlthereof sends a signal to the light source console 28 indicating thatthe endoscope 22 does not have the distal window 99, thereby notallowing the source 104 of heating light to activate at step 416.Conversely, if the camera 73 or control thereof does not identify thepattern at step 414, then the camera 73 or control thereof sends asignal to the light source console 28 indicating that the endoscope 22does have the distal window 99 such that the heating light can beemitted by the light source console 28 at step 418.

For example, the light source console 28 can emit IR light (from thesource 104 of heating light or from another source) up to about 800 nmwavelength, with the distal window 99 preventing passage ofelectromagnetic waves having a wavelength greater than 700 nm. It iscontemplated that the source 104 of heating light could be an LED. Ifthe camera 73 or control thereof senses light having a wavelengthbetween 700 nm and 800 nm, then the camera 73 or control thereof willinstruct the light source console 28 to turn off the source 104 ofheating light because the endoscope 22 does not have the distal window99. However, if the camera 73 or control thereof senses light having awavelength between 700 nm and 800 nm, then the camera or control thereofwill instruct the light source console 28 to use the source 104 ofheating light because the endoscope 22 does have the distal window 99.It is contemplated that the second method 410 for determining if theendoscope 22 includes the distal window 99 could be used in conjunctionwith a scope-detection technique to ensure that the endoscope 22 withthe distal window 99 is being used. It is contemplated that the patternof electromagnetic waves could be sent to be sensed (or not sensed asthe case may be) continuously, only at the beginning of use of theendoscope 22 or periodically to establish higher confidence of use ofthe endoscope 22 with the distal window 99 and to detect any change inthe endoscope 22 during a surgical procedure.

A third method 420 (FIG. 9C) for determining if the endoscope 22includes the distal window 99 is to use the temperature sensitive cap110 described above to verify that the endoscope 22 includes the distalwindow 99 by confirming (or not confirming as the case may be) theabsence of heating light being emitted from the endoscope 22 when thetemperature sensitive cap 110 is placed on an end of the endoscope 22.The third method 420 includes emitting heating light from the endoscope22 at step 422. If the heating light (or a threshold amount of theheating light if the distal window 99 is not 100% absorptive of theheating light) is detected by the cap 110 at step 424, the temperaturesensitive cap 110 can send a signal instructing the light source console28 to turn off the source 104 of heating light because the endoscope 22does not have the distal window 99 at step 426. If the heating light isnot detected at step 424, the temperature sensitive cap 110 can send asignal to the light source console 28 instructing the light sourceconsole 28 to use the source 104 of heating light because the endoscope22 does have the distal window 99 at step 428.

In the illustrated example, it is contemplated that the temperaturesensitive cap 110 can communicate with the light source using any of themethods described above for communicating information from thetemperature sensitive cap 110 to the light source console 28. Theheating light and the imaging light can be distinguished by thetemperature sensitive cap 110 using a frequency-limited sensor thatsenses the heating light, using filter optics that allow the heatinglight which passes thereby to be sensed by a sensor or by having thelight source console 28 sequentially modulate the imaging light and theheating light in order to allow the temperature sensitive cap 110 todetect the imaging light and detect the absence of the heating light (ifthe endoscope 22 includes the distal window 99).

A fourth method 430 (FIG. 9D) for determining if the endoscope 22includes the distal window 99 is to add a sensor 200 to the housing 125of the light source console 28 as shown in FIG. 11, emit heating lightat step 432 and point the endoscope 22 at the sensor 200 at step 434 toverify that the endoscope 22 includes the distal window 99 by confirming(or not confirming as the case may be) the absence of heating lightbeing emitted from the endoscope 22 at step 436. If the heating light isdetected at step 436, the light source console 28 turns off the source104 of heating light because the endoscope 22 does not have the distalwindow 99 at step 438. If the heating light is not detected at step 436,the light source console 28 will use the source 104 of heating lightbecause the endoscope 22 does have the distal window 99 at step 440.

In the illustrated embodiment, the heating light and the imaging lightcan be distinguished by the sensor 200 using a frequency-limited sensorthat senses the heating light, using filter optics that allow theheating light which passes thereby to be sensed by a sensor or by havingthe light source console 28 sequentially modulate the imaging light andthe heating light in order to allow the sensor 200 to detect the imaginglight and detect the absence of the heating light (if the endoscope 22includes the distal window 99).

Communicating Endoscope

FIG. 12 illustrates another embodiment of the endoscope system includinga communicating endoscope 22 c. Since communicating endoscope 22 c issimilar to the previously described endoscope 22, similar partsappearing in FIGS. 1-3A and FIG. 12, respectively, are represented bythe same reference number, except for the suffix “c” in the numerals ofthe latter. The communicating endoscope 22 c includes the shaft 23 c andthe light port 58 c. A plurality of optic fibers 210 run from the lightport 58 c to provide the heating light to the distal window 99 c to heatthe distal window 99 c along with providing imaging light to the distalend 27 c of the endoscope 22 c as described above. The plurality ofoptic fibers 210 extend between the tubular outer housing 61 c and theinner tubular housing 63 c of the shaft 23 c. Some of the optic fibers210 also run from the light port 58 c to a control and communicationsystem 212 within the endoscope 22 c. The communicating endoscope 22 cis configured to be connected to the light source console 28 having thesource of imaging light 102, the source of heating light 104, the mirror106, and the detector 152 as described in FIG. 6 above. It iscontemplated that light pipe(s) could be employed instead of opticfibers 210.

In the illustrated example, the control and communication system 212 inthe communicating endoscope 22 c receives power from the light sourceconsole 28 and communicates information to the light source console 28.The control and communication system 212 comprises an integrated circuithaving a microcontroller 214, a photo cell 216, an electromagnetic lightemitter 218 and a detector 220. The microcontroller 214, theelectromagnetic light emitter 218 and the detector 220 are all poweredby the photo cell 216. The illustrated photo cell 216 is connected to aplurality of the optic fibers 210 and receives heating light and imaginglight from the light source console 28. In the illustrated example, theheating light and the imaging light are multiplexed in the output of thelight source console 28 and/or the transmission cable 46 without theheating light and the imaging light being separated when entering orwithin the communicating endoscope 22 c. Therefore, the photo cell 216will receive heating light and/or imaging light during use. However, asdiscussed in more detail below, the heating light, the imaging lightand/or a third wavelength of light can be separated when entering thecommunicating endoscope 22 c or within the communicating endoscope 22 csuch that only a selected wavelength of light reaches the photo cell 216from the light source console 28. The light reaching the photo cell 216causes the photo cell 216 to power the components of the communicatingendoscope 22 c that require power or stores the power in the control andcommunication system 212 for later use. The photo cell 216 allows forefficient energy storage collection, thereby allowing the energy to betransformed to usable levels and stored for future high power demandprocesses and also provides a means for allowing the electromagneticlight emitter 218 to communicate with the light source console 28 asdiscussed below (including communicating the status of the stored chargein the control and communication system 212).

The illustrated control and communication system 212 communicatesinformation to and from the light source console 28 in order toefficiently operate the communicating endoscope 22 c. The control andcommunication system 212 can include the electromagnetic light emitter218 connected to at least one optic fiber 210 for communicating with thelight source console 28. The electromagnetic light emitter 218 can emitany wavelength of light under control of the microcontroller 214 to senda signal or signals to the light source console 28. It is contemplatedthat the electromagnetic light emitter 218 can be at least one LED. Thedetector 220 receives the heating light, the imaging light and/or athird wavelength of light to communicate to the control andcommunication system 212 that the light source console 28 is capable ofreceiving and using the data sent by the electromagnetic light emitter218. If the detector 220 does not receive information that the lightsource console 28 is capable of receiving and using the data sent by theelectromagnetic light emitter 218, the control and communication system212 will turn off the electromagnetic light emitter 218 or otherwiseprevent the electromagnetic light emitter 218 from sending data. Thedetector 220 can be any detector capable of detecting a certainwavelength of light. For example, the detector 220 can be an infraredphotodiode. It is contemplated that the communicating endoscope 22 ccould be used without the electromagnetic light emitter 218.

In the illustrated example, a plurality of sensors 222 can befunctionally connected to the microcontroller 214 for sensing propertiesof the communicating endoscope 22 c. For example, the communicatingendoscope 22 c can include a temperature sensor 224 adjacent the distalwindow 99 c for sensing a temperature of the distal window 99 c. Thecontrol and communication system 212 can communicate the temperature ofthe distal window 99 c as sensed by the temperature sensor 224 to turnon or off the source 104 of heating light as needed to maintain thedistal window 99 c at a desired temperature. The sensors 222 can alsoinclude an exterior temperature sensor, at least one accelerometer, ahumidity sensor, an air/gas content sensor, a proximity sensor, anexterior pressure sensor, a force sensor and/or a sensor for detectingwaves (e.g., radio frequency waves, infrared light, visual light,ultraviolet light and/or magnetic waves).

The illustrated sensors 222 can be used to communicate properties of thecommunicating endoscope 22 c to the light source console 28. Forexample, the at least one accelerometer and/or the force sensor cansense if the communicating endoscope 22 c has had a dramatic change inacceleration such when the communicating endoscope 22 c is dropped orotherwise violently moved to communicate that the communicatingendoscope 22 c may be broken. Additionally, the exterior pressuresensor, the humidity sensor, the air/gas content sensor, and/or theexterior pressure sensor can be used along with an internal timer withinthe microcontroller 214 to determine if the communicating endoscope 22 chas been cleaned (e.g., through autoclaving) and/or cleaned for apredetermined period of time. If the communicating endoscope 22 c hasnot been sufficiently cleaned, the communicating endoscope 22 c cancommunicate with the light source console 28 to notify a user of theendoscope system that the particular communicating endoscope 22 c shouldnot be used without further cleaning. The sensors 222 can also be usedto determine if other cleaning methods (e.g., exposure to ultravioletlight) have been used and communicate the sufficiency of cleaning usingthis method to the light source console 28. Additionally, one of thesensors 222 could be used to measure the temperature of the shaft 23 cof the communicating endoscope 22 c and communicate the same to thelight source console 28 to allow the light source console 28 to turn offif the shaft 23 c is too hot (e.g., because of, for example, thecommunicating endoscope 22 c being used in an improper environment suchas when the communicating endoscope 22 c is intended for use in afluid-filled joint is then improperly used in an ENT procedure wherethere is no fluid present to help keep the communicating endoscope 22 ccool). A temperature sensing sensor 222 could also be used to shut offthe power of temperature sensitive components of the control andcommunication system 212 if the exterior temperature raises above acertain temperature. Moreover, the communicating endoscope 22 c could beconfigured to send periodic transmissions to the light source console 28(e.g., signals representing that the status of the communicatingendoscope 22 c is functioning properly) so that hazardous conditionssuch as accidental disconnection of the transmission cable 45 from thecommunicating endoscope 22 c could be detected from the loss of theperiodic transmissions and the source 102 of imaging light could beturned off to prevent the high-intensity imaging light from escaping adisconnected end of the transmission cable 48 to prevent injuries (e.g.,eyesight damage and/or burning).

The illustrated communicating endoscope 22 c could also communicateother information not sensed by the sensors 222 to the light sourceconsole 28. For example, the communicating endoscope 22 c couldcommunicate the type of endoscope as saved in memory in themicrocontroller 214 (for example, to allow the light source console 28to configure itself to maximized compatibility of the communicatingendoscope 22 c with the light source console 28), a lifetime of thecommunicating endoscope 22 c (calculated, for example, using a clock inthe CPU or by including information when the communicating endoscope 22c was manufactured), service hours of the communicating endoscope 22 c(measured, for example, by the total time that the detector 220 hasreceived light), and operational information of the particularcommunicating endoscope 22 c. Another example of informationcommunicated from the communicating endoscope 22 c to the light sourceconsole 28 can be the capability of the communicating endoscope 22 c touse advanced imagining techniques (for example, capability of readinginfrared wavelengths given off by indocyanine green dye in a patient).

FIG. 13 illustrates a second embodiment of the communicating endoscope22 d. Since the second embodiment of the communicating endoscope 22 d issimilar to the previously described first embodiment of thecommunicating endoscope 22 c, similar parts appearing in FIG. 12 andFIG. 13, respectively, are represented by the same reference number,except for the suffix “d” in the numerals of the latter. The secondembodiment of the communicating endoscope 22 d is substantiallyidentical to the first embodiment communicating endoscope 22 c, exceptthat the fiber optics 210 d do not connect to the cell 216 d (althoughthe fiber optics still do connect to the electromagnetic light emitter218 d and the detector 220 d). Instead of light powering the cell 216 d,the cell 216 d can be powered by another source. For example, the cell216 d can be powered by thermal energy, vibrations, radio frequencywaves or inductive transducers using methods well known to those skilledin the art. If an inductive transducer is used, the cell 216 d can besupplied with power by an inductive coupler on the camera or could be along-range resonant magnetic coupler positioned near the endoscope whensame is not in use.

FIG. 14 illustrates a third embodiment of the communicating endoscope 22e. Since the third embodiment of the communicating endoscope 22 e issimilar to the previously described second embodiment of thecommunicating endoscope 22 d, similar parts appearing in FIG. 13 andFIG. 14, respectively, are represented by the same reference number,except for the suffix “e” in the numerals of the latter. The thirdembodiment of the communicating endoscope 22 e is substantiallyidentical to the second embodiment communicating endoscope 22 d with thefiber optics 210 e not connected to the cell 216 e, except that thefiber optics 210 e also do not connect to the electromagnetic lightemitter and the detector. Instead of communicating the light sourceconsole 28 with the fiber optics 210 e and the transmission cable 46,the electromagnetic light emitter 218 d is replaced with a wirelesssending device 218 e and the detector 220 d is replaced with a wirelessreceiving device 220 e (or the wireless sending device 218 e and thewireless receiving device 220 e can be combined into a single unit). Forexample, the wireless sending device 218 e and the wireless receivingdevice 220 e can communicate using a low power wireless or WPANconfiguration, employing a wireless communication protocol that has alimited communication distance (e.g., Zigbee, Bluetooth, SimpliciTI andANT).

FIG. 15 illustrates a fourth embodiment of the communicating endoscope22 f Since the fourth embodiment of the communicating endoscope 22 f issimilar to the previously described first embodiment of thecommunicating endoscope 22 c, similar parts appearing in FIG. 12 andFIG. 15, respectively, are represented by the same reference number,except for the suffix “f” in the numerals of the latter. The fourthembodiment of the communicating endoscope 22 f is substantiallyidentical to the first embodiment communicating endoscope 22 c, exceptthat the fiber optics 210 are replaced with a light splitting and/orcombining device 250. The light splitting and/or combining device 250will redirect electromagnetic waves 252 coming from the light sourceconsole 28 and the transmission cable 46 and redirect the redirectedelectromagnetic waves 254 toward the distal window 99 f and the controland communication system 212 f. It is contemplated that the lightsplitting and/or combining device 250 could be a prism or prisms, adichroic splitter/combiner, a fractional splitter/combiner (e.g., a halfsilvered mirror), or a wavelength-division-multiplexing module). It iscontemplated that the light splitting and/or combining device 250 couldredirect a certain band or certain bands of wavelength of light towardthe distal window 99 f (e.g., the heating light and the imaging light)while redirecting a third band of wavelength of light or allowing thethird band of wavelength of light to pass therethrough (e.g., lightgoing to and/or from the control and communication system 212 f). It isalso contemplated that free space coupling could be used.

In all of the communicating endoscopes 22 c-22 f described above, all ofthe features could be used with any of the communicating endoscopes 22c-22 f. For example, the communicating endoscopes 22 c-22 f could beused with a distal window 99 that heats to prevent fogging. Furthermore,the communicating endoscopes 22 c-22 f could be used with a cell 216that receives power from light or from other means as described above,or all of the communicating endoscopes 22 c-22 f could be used with theelectromagnetic light emitter 218 and/or the detector 220 (i.e., one orboth thereof) that communicate using light through the transmissioncable 46 or through any wireless methods as described above. Finally,any of the communicating endoscopes 22 c-22 f could be used with orwithout the sensors 222 described above.

Although the present invention has been described with reference tospecific exemplary embodiments, it will be recognized that the inventionis not limited to the embodiments described, but can be practiced withmodification and alteration within the spirit and scope of the appendedclaims. Accordingly, the specification and drawings are to be regardedin an illustrative sense rather than a restrictive sense. For example,the foregoing has involved surgical procedures specific to humans. Itwill be appreciated that the systems and methods described herein mayalso be applied to veterinary applications and non-biologicalapplications, for example for inspection of fluid chambers in industrialplants and transport devices. Moreover, it is contemplated that any ofthe approaches for selecting or setting the power level of the heatinglight can be used in conjunction with any of the methods for determiningif the endoscope 22 includes the distal window 99. Moreover, it iscontemplated that the distal window 99 of the present invention could beused on an endoscope having chip on tip technology wherein the chipemits light (e.g., an LED), with the chip emitting a broad spectrum oflight including both the imaging light and the heating light, aplurality of chips emitting imaging light and heating light, and/or acombination of at least one chip and light coming from the light sourceconsole 28.

Although particular preferred embodiments of the invention have beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, includingthe rearrangement of parts, lie within the scope of the presentinvention.

What is claimed is:
 1. A method for defogging an endoscope during asurgical procedure, the method comprising: illuminating a target with anilluminator; capturing at least one image of the target by an endoscopicimaging system via the endoscope; detecting fogging on at least oneoptical surface of the endoscope by analyzing the at least one image;and in response to detecting fogging on the at least one optical surfaceof the endoscope, defogging the at least one optical surface of theendoscope by controlling the illuminator to increase a temperature ofthe at least one optical surface of the endoscope via light from theilluminator.
 2. The method of claim 1, wherein the at least one opticalsurface is located at a distal end of the endoscope.
 3. The method ofclaim 2, wherein the at least one optical surface comprises a distalwindow of the endoscope.
 4. The method of claim 1, wherein the at leastone optical surface of the endoscope comprises a transparent window. 5.The method of claim 1, wherein controlling the illuminator to increasethe temperature of the at least one optical surface of the endoscopecomprises increasing a power level of the illuminator.
 6. The method ofclaim 1, wherein controlling the illuminator to increase the temperatureof the at least one optical surface of the endoscope comprisescontrolling the illuminator to provide infrared light to the endoscope.7. The method of claim 1, wherein controlling the illuminator toincrease the temperature of the at least one optical surface of theendoscope comprises controlling the illuminator to simultaneouslyprovide both infrared light and visible light to the endoscope.
 8. Themethod of claim 1, wherein controlling the illuminator to increase thetemperature of the at least one optical surface of the endoscopecomprises transmitting a signal to the illuminator to cause theilluminator to enter a defogging mode for heating the at least oneoptical surface of the endoscope.
 9. The method of claim 1, whereincontrolling the illuminator to increase the temperature of the at leastone optical surface of the endoscope comprises heating the at least oneoptical surface of the endoscope to body temperature.
 10. The method ofclaim 1, wherein the endoscopic imaging system is configured to captureinfrared images.
 11. The method of claim 1, wherein controlling theilluminator to increase the temperature of the at least one opticalsurface of the endoscope is based on one or more automaticallytransmitted endoscope specific parameters.
 12. The method of claim 1,further comprising decreasing an amount of light provided to theendoscope after a predetermined period of defogging time.
 13. The methodof claim 1, wherein detecting fogging on at least one optical surface ofthe endoscope by analyzing the at least one image comprises animage-processing analysis.
 14. The method of claim 1, wherein:illuminating the target comprises directing light from the illuminatorthrough a light guide of the endoscope; and defogging the at least oneoptical surface of the endoscope comprises controlling the illuminatorto increase a temperature of the at least one optical surface of theendoscope via the light from the illuminator that is directed throughthe light guide of the endoscope.
 15. A system comprising: anilluminator for illuminating a target via an endoscope; and anendoscopic imaging system comprising an endoscopic camera for couplingto the endoscope, the endoscopic imaging system configured for:capturing at least one image of the target via the endoscope, detectingfogging on at least one optical surface of the endoscope by analyzingthe at least one image, and in response to detecting fogging on the atleast one optical surface of the endoscope, controlling the illuminatorto increase a temperature of the at least one optical surface of theendoscope via light from the illuminator to defog the at least oneoptical surface of the endoscope.
 16. The system of claim 15, whereinthe endoscopic imaging system comprises a camera and a cameracontroller.
 17. The system of claim 15, wherein the illuminator isconfigured to increase the temperature of the at least one opticalsurface of the endoscope via light generated from at least one LED. 18.The system of claim 15, wherein the illuminator is configured toincrease the temperature of the at least one optical surface of theendoscope via light from at least one infrared laser.
 19. The system ofclaim 18, wherein the illuminator is configured to simultaneouslygenerate light from at least one LED while providing light from the atleast one infrared laser.
 20. The system of claim 15, wherein theilluminator has an illuminating mode for illuminating the target and adefogging mode for defogging the at least one optical surface of theendoscope and the illuminator is configured for switching between theilluminating mode and the defogging mode.
 21. The system of claim 15,wherein the endoscopic imaging system comprises the endoscope.
 22. Thesystem of claim 21, wherein the at least one optical surface is locatedat a distal end of the endoscope.
 23. The system of claim 21, whereinthe at least one optical surface comprises a distal window of theendoscope.
 24. The system of claim 21, wherein the at least one opticalsurface of the endoscope comprises a transparent window.
 25. The systemof claim 15, wherein controlling the illuminator to increase atemperature of the at least one optical surface of the endoscopecomprises increasing a power level of the illuminator.
 26. The system ofclaim 15, wherein controlling the illuminator to increase a temperatureof the at least one optical surface of the endoscope comprisestransmitting a signal to the illuminator to cause the illuminator toenter a defogging mode.
 27. The system of claim 15, wherein theendoscopic imaging system is configured to capture infrared images. 28.The system of claim 15, wherein controlling the illuminator to heat theat least one optical surface of the endoscope is based on one or moreendoscope specific parameters stored in a memory of the endoscopicimaging system.